Train-control system



Dec. 15. 1925- P. J. SIMMEN TRAIN CONTROL SYSTEM Filed April l5 Patented Bec. l5, 1925.

UNITED STATES PAUL J'. SIMMEN, OF EDEN, NEW YORK.

TRAIN-CONTROL SYSTEM.

Application filed April 15, 1922. Serial No. 553,204.

To all whom t may concern:

Be it known that I, PAUL J. SIMMEN, a citizen of the United States, residing at Eden, in the county of Erie and State of New York, have invented certain new and useful Improvements in Train-Control Systems, of which the following is a specifica-- tion` This invention relates to train control systems of the broad or general type wherein train movements are regulated by central oiiice apparatus under the control of a despatcher and train movement regulating devices (such, for example, as signals) carried by the vehicle are severally responsive in operation to particular electrical conditions of short third rails or ramps placed at the entrance of stations or block divisions of thc line. The deenergized condition of the third rails is one of the electrical conditions thereof to which the train movement regulating means is responsive and is utilized to produce an operation of said means which will conform to .danger conditions, for example, the display of a danger'signal.

The principal object of the invention is to give the despatcher fuller and more certain information concerning train movements and greater facility in the control of such movements and the utilization of track capacity.

A, further object of the invention is to provide a record by which the (le-energized condition of the third rail and the movement of the train in relation to such deenergized rail can be established as occasion may require.

Generally stated, the invention consists in thc provision of an electric circuit which is established automatically between the central office and the vehicle through the third rail which was cle-energized to produce an operation of said train movement regulating means conformable to danger conditions,

fwhich circuit shall be contemporaneous with, and without effect-on, the said operation of said means and may be utilized as desired for the purposes of train control; the invention further consists in provision for the operation of an element of the central office apparatus responsively to the movement of the vehicle in relation to a deenergized third rail, such operating element preferably being a recording element whereby a recordvof the movements of vehicles in relation to third rails which have been deenergized to produce an operation of the train movement regulating means conformable to danger conditions may be effected and maintained.

The invention further consists generally in novel features of structure and combination appertaining to the transmission of electrical currents 'between the central oflice and the vehicle through the third rails and also to the recording at the central office of the movements of the vehicle in relation to de-energized third rails.

The invention is illustrated in the accompanying drawing wherein:

Figure 1 is a schematic diagram showing the apparatus at the despatchers office in relation to the track of the railroad.

Figure 2 is a schematic diagram of the cab circuits and equipment.

Along the track 1, which may be assumed to run east and west are a number of stations A, B, C, D, E, etc., which may be actual stations or other convenient dividing points between blocks, station A. being assumed to be a terminal of the road or of a division thereof. At the eastern and western entrance of each station there is a siding 2, which in the diagram of Fig. 1 is shown disproportionately large in relation to the distance between adjacent stations or blocks. The signal rails, that is to say the short third rails or ramps, are also provided at the eastern and western entrance of eacn station, and, preferably and in accordance with known practice, are connected in pairs, each pair comprising a Lhome rail 3 and a distant rail 4.-, these rails being conveniently located on the right hand side of the track for each direction of train movement. The car or locomotive indicated diagrammatically by the showing of the truck T is provided with a movable shoe 5 for engagement with the signal rails, the arrangement being such that the shoe 5 will first engage the distant rail and thereafter the home rail.

The different cab circuits are controlled by different electrical conditions of the rails 3 and 4, and in the embodiment selected for the purpose of illustration include signal lamps as the regulating devices. An energized condition of the third rails produces of illustration-itis. assumed-tliatthe.rails a clear signal and a de-energized condition produces a danger Signal. For the purpose are to -be energized .by direct current."'

The cab circuits and the signal lamps lor regulating train movements are shown in Figure 2. A simple arrangement of twolamp circuits, such as is shown in vmy prior- Patent, No. 941,541 of November 30, 1909, has been-selected for the purpose of illustration. The car carries a relay CR which may Ybe'otfanyfdesiredcharacter'and is used to ther signal vlamp s.I`

control-the operations7 of 'lhe relay i CRpas zshcvvn, includes an ordinaryuna'gnet*6andy a pivoted armature 7 which .fmoves againsta rontcontact 8 when the magnet is energized and against a back contact) =when :the magnetfis cle-energized. The magnetL plied throughthe third rails-l lor by current supplied-from a suitable source, for example, a battery' 10 carried by the car.' Vhen the shoe 5 is'engaged With an electrified third rail 3-4 current-flows byv'the vire 11 to the magnet 6 and thence by thewires'lZ and 13 to ground. 'lVhen thefshoeis engaged with a de-energized third- 'rail no' current is supplied 'to the-,magnet 6. Vhen the shoe 5 passes romf an energized third rail current is supplied to' fthe\ma'gnet Iby vthe. battery 10 andithey energiz-ation of the rmagnet is thus continued until it iszinterrupted, as will presentlyfappear, by the engagement ofthe shoe5 Witha deenergized third rail. W'hen the shoe -passes'fromia de-energized third rail no currentwissupplied tozthe magnet Whichthus remainsv de-energized until such timeras-its energization yis established-by the engagement ofthe 'shoe' with an energizec third rail. VVh'entlie magnet 6is energized a clear signal-v is displayed and when the magnet'G-is de-energized -a.-danger signal is displayed, the clear fsignalbeing given .by a green lampgli' anditheffdangersignal by a red lamp :15.

One pole otthebattery 1U is permanently connected to the armature -7 and said battery is ina-normally maintained circuit Which establishedf'the lighting ofthe clear signal lain'pglflc. Such circuit includes thev magnet 6, the -'armature7,. the front contact 8 `and the" Wires-11 and 12 and=is completed by asuitable-switch 16 l'movable With the shoe 5 and normal-ly y(i-. e. vwhen said shoe is not engaged Witha third rail) 'engagingza contact 17 *connected'by ya -Wir'e 18 tothe front contact 8. This circuit may beftraced as follows: battery 10, armature- 7, front con-.r tact 8, Wire 18, contact 17, switch 16, shoe 5,' Wire11l,'.magnet fandwires 12 and19 to battery; The lcircuit thus -traced'is broken at =thecontact 17 When-the shoe 5 is in'engagement with a third rail.

VheIr the'magnet 6=is energized another circuit is established for the lamp 14 and 6 'is' energizedy by current supswitch 16 Willengage ger signal which is wire 20, lamp 14, and Wires 21, 19a and 19 to 7i battery.

Vhen' the magnet 6 is de-energized a circuit is established for the lamp 15 and which may utilize the battery 10 or other suitable source. As shown,the circuit for the lamp 7 15 may be traced from battery 10 through armature 7, baclr contact 9, Wire 2.2, lam-py 15, and Wires 23, 19a and 19 to battery.

It Will be noted-that the particularsignali established in :accordance with the condition s of the third rail With Whichxthe shoe =5 is: engaged is continued as the vehicle passes by the-third rail and untilthe-shoe 5 engaged with a third rail having a differenti. electrical condition. ormed,fin accordance-.with standard practice, wth inclined end portionstnot shown) to facilitate the engagement'ostheshoe 5 y andwthe parts arevso arranged that the the contact 17 before s the 'shoe 5 completel-y disengagesthe third i rail. Consequently,l in the caseof an energized third rail, the energization of themag= net effected through the circuit in which said third rail is included-is uninterrupted con 1 tinued when vthe vehicle passes beyondthe' third rail by the local holding feircuitlwhich includesthe battery 10 and the switchlG; and in this way the lighting oiiy the lamp 14 to give a clearsignal as-eli'ected by the'con'A tact of the shoe'wvith an energized-'third rail is continued `until the shoe 5 engages'a de-energized'third rail, at which time, the

l local holding circuit being broken at the conf-l tact 17, no current is supplied to-the mag-N net 6.

Then the magnet is thus de-energizedbyl the engagement of the shoe 5 With.ade'en ergized third rail, the armature 7 falls against the back contact 9 and closes the circuitof the lamp 15, thus producing the dans. continued until the shoe 5 engages an energized rail, it beingapparentthat after the vehicle leaves a de-energ gized'rail the localfholding circuit fot the magnet is broken at the contact 8,1andthearmature-7 will remain 'in engagement with.. thev contact -9 until such time as current is supplied to the magnet 'through'y an energized third rail.

Theelectrical conditionof the :third rails is subjectfto-control by vswitches at the despatchers oiice' andv which are designated generally as26, there being a switch for each station' orblock divisions which they control. In the present diagram it is assumed that each switch is connected to the third rails at .the adjacenteastern and Western entrancesof adjacent blocks. The switches are indicated merely` diagrammatically in rllhe -third railris E the drawings and are differentiated by the same letters as the stations to which they severally correspond. As shown, they include rocker shafts 27 by which they are mounted and each shaft is connected. by a wire 28 to the signal rails 3 4 of the corresponding stations.

Any suitable arrangement may, of course, be provided for supplying current to the third rails .in connection with their control from a remote point i. e. the despatchers oiice. As herein shown the third rails are energized by current supplied from a common battery 29 which is connected by a line wire 30a to a rail of the track 1 and which may be utilized as the source of current for certain electrical receiving devices at the despatchers office. The other pole of tho battery 29 is connected to the stationary contacts of the switches 26, the connection including a common wire 30 and wires 31 and 32 leading to the switch contacts. The central station equipment may include station relays DR for a purpose to be described and the magnets 33 of said relays are shown as connected between the wires 31 and 32.

The circuit from the battery 29 through a third rail is completed by the engagement of the shoe 5 of the car with such third rail and by the closure of the corresponding switch 26, the switches AB 26, CD 26, and DE 26 being shown as closed. The despatcher can at any time de-energize the third rails at the entrance oi any block in order to effect a danger signal when the shoe 5 of the approaching vehicle engages vsuch third rails. This is accomplished by disengaging the stationary and movable contacts of the battery 29 at the switch; the drawing shows the switches BC 26 and Ef 26 as thus opened, thereby to de-energize the third rails at the adjacent entrances of blocks B and C and E. and F.

The system includes suitable apparatus at the despatchers office for making a record olf train movements and one form of such apparatus is herein shown diagrammatically. As shown the recording apparatus includes a chart 39 in the form of a web and which is trained over any suitable arrangement of guiding and winding rollers. The web 39 bears regularly spaced transverse or horizontal lines 40 indicative of divisions of time and longitudinal or vertical lines 41 and 41l1 indicative of the staj tions to which they severally correspond, as

shown in the drawings by the lines AB, BC, CD, DE, and EF, etc. The shaft 4 2 of the winding roll of said web may be clock driven in any suitable manner but it is preferably driven by a ratchet Wheel 43 in turn operated by a pawl 44 carried by the armature of an electro-magnet 45. Current for the operation of the magnet 45 is supplied by a battery or other suitable source 46, the circuit being traced asy follows: battery 46, wires 47 and 48, clock switch 49, Wire 50, magnet 45 and wires 51 and 52 to battery.

The system includes means for recording the movements of the vehicle in relation to station or block divisions for which clear signals have been given and the devices for making such records are conditioned for operation by the despatcher, their co-ordination being e'ected by the station relays DR by which the operating circuits of said devices are controlled. For the purpose of recording the movements of the vehicle in relation to station or block divisions for which clear signals have been given it is preferred to employ punches 53 which forni recording perforations in the chart and are arranged to operate on or adjacent the lines 41. The punches 53 are operated by magnets 54 which are energized by current from the battery 46 or other suitable source. The circuit of the magnet 54 provided for a particular station or block division is completed when a vehicle has its shoe 5 in engagement with an energized third rail at the entrance of such station or block division. The drawings show such a vehicle in block C and the diagram assumes that the shoe 5 of the vehicle is engaged with the energized third rail 4 at (i. e. suitably in advance of) the entrance of block D. In such case the relay DR for station C is energized and the circuit of the corresponding magnet 54 may be traced as follows: battery 46, wiresl 47 and 49, armature 55 and front contact 56 of relay DR, Wire 57, magnet 54 and wires 58, 59 and 52 to battery 46. In all cases the circuits of magnets 54 are completed by corresponding armatures 55 in engagement with their front contacts 56 and hence for their completion it is required that the relays DR be energized. Since these relays can never be energized except as the corresponding third rails are electrified by current supplied by the battery 29, it follows that under danger conditions when the third rails are de-energized no operation of the corresponding punch 53 can take place.

The invention provides for the operation of an element of the central otiice apparatus responsively to the movement of the vehicle in relation to a de-energized third rail and also provides for an electrical circuit between the central office and the vehicle through the third rail which was deener gized to produce an operation of the train movement regulating means conformable to danger conditions, i. e. an operation of the danger signal, which circuit is contemporaneous with, and without effect on, the danger signal. The central oice element which operates responsively to the movement of the vehicle in relation to a de-energized third rail is preferably a recording element, (which may be conveniently designated at a dead rail recording A element) in eo-operation with the chart; and the circuitbetween the central officeandi the'vehicle is preferably used to produce the-operation of E such recording element.

The deadrail recording felenfients'arelpro-- vided for the several'station or blockidivisionsof the road and preferably fconsist 'of perforating punches -60 I.arranged to opltr-crater onior adjacen lithe dimes-41,- Then punches 60 are operated by magnets 61,

which are. supplied with current. fromany;l

suitable source,1 preferablyl ,the battery .46, theoperating :circuits of the', magnets. 61 'belering controlled. in the embodimntdisclosed by station.' relays ARf and being closed through the arma-tures 62f-and .front -contacts' 63 of said relays when the vmagnets 6-1 thereof 'are energized. The' circuit of the acrmag'net 61 correspondingto station E is shown' as closedsand may-fbe traced as fol-A lows: battery 46, lWires-17 and 49,- arniature 62, front contact 63,.-wii'e '65,.' magnet 61 and wires 66, y59 'and '5,2 to'battery.

er Tliecurrent'- which'supplies the relays A R differs 'markedly' Afrom 'the cur-rent which is nori'n'all-y wWhere, 'as in the' 'presentl'embodimenn the current normally supplied :to the third rails preferred Ivto use alternating' mnflSI dll'Gl v current for lthe relays :ART The.' alternating ,current `generator maybe vlocated at the central -oflie'e but' preferably, and` as shown, is carried `byf'the vehicle, being indi by Wires'68 to a rail of the track 1 and by Wires 69 to contacts 70 'Which are engaged by auXiliaryarins 1`ofth'e switches 26 only when said switches are opened. One. pole v.of the 'generator 'isjconnected to ground by a Wire 72 and'theother'pole 'is `connected to an armature 7 3 coupled to the varmature 7 and, when `the .magnet "6 'is deenergized, engaginga back 'contact 7llconnected by a Wire 75 to a contact 7 6`Whicliis engaged by the switch '16 When'tlie shoe/5 is in engage'- ment withv a third 'rail The Acircuit of the generator 67 Athrough' any relay AR' upon'a de-energiz'ed'third railxthe magnet 6 is de-energized and .the danger signal is eofgiven by the red lamp 15 in. the manner above explained and as shown in Figure A At' the same time the circuit of the generator 67 through the relay AR corresponding to said initially de-energized rail is' supplied' to the third 2 rails.,

nicated at 67.' Thfmagnets 6% are-connected and l13,2 condenser 73 andl condensers 7 9 are completed through said. rail Without ,af-

fceting the danger signal. inthe present enibodimentthis@ is due tothe impedances 77 which prevent .theflowi of alternating current to the magnet -6. In the diagram the circuit' of the relay Altof station E is assumed to be closed and may be traced as follows: generator 67, Wire 7Q,.-a -rail of track 1, wireGS, magnet v6i, of relayAR, Wire 69 to contact 70 and auxiliary arm 71, shoe. 5, switch 16, contact 76, Wire 7 5, con-. tact 7 el andarmature .7i-3 to generator. The

energizationnof a relayAR .produces an,

operation -of the corresponding punclifflt) which thus makes a perforation in the chart 39 each time that the shoe 5 passes over a (le-energized -tl'iiid rail.

Having described my inventioml claim:

1. In a system of trainrontrol, vthecombinationv with a vehicle and a line of track, ofy an element associated with the track ya nd upon which elect 1ic current may be iinpressed, manually operated central officeA means for energizing or de-energizing said element, electrical receiving`-devices'in the.

\eliicle, means for severally conditioning said devices in accordance 'with the -condif tion of said elementas effected by .saidcentral office means, means involving the co-op-..

eration of said vehicle and said element as initially de-energized by said central office' means for automatically establishing an.

electric circuit between said vehicle andthe central oflice and an electrical receiving device in said circuit.

2. In a system of train control,v the combination With a vehicle and a line ofj track, of an element associated with the` track and -upon lwhich electric current may 'be impressed, central ofiicc-means for energi'z-v.

ing or de-energizing said element,ele'ctrical' receiving devices in the vehicle, means for severally conditioning said devices in. ac

cordance with tliecondition of said element as effected by said first named means, means involving the co-operation of said vehicle and said element as initially.de-energized by said first named means for automatically .establishing an electric circuit between,

said vehicle and the centra-l office and an electrical receiving device in said circuit,

3. In a system of train control, the com-i bination with a vehicle-and a line of track,

of an element associated, with the track and upon Which electric current may be impressed, manually operated central' ofiice means for energizing or de-energizing said element, electrical receivingdevices in .the

vehicle, means lfor severally conditioningsaid devices in accordance with the conditions of said element as effected by said central office means, recording means 'at the central office, and means vinvolving the cooperation of said vehicle and said element' as initially de-energized by said central oiiice means for producing an operation oi said recording means.

al. in a system of train control, the combination with a vehicle and a line et track, et an element associated with the track and Upon which electric cu 1rent may be iinpressed, central otlice means for energizing or Cle-energizing said element, electrical receiving devices in the vehicle, means for severally conditioning said devices in accordance with the condition of said element as effected by said first named means, recording means at the central otiice, and means involving the co-operation oi said vehicle and said element as initially deenergized by said first named means -tor producing an operation ot said recording means.

5. In a system ot train control, the combination With a vehicle and a line of track, oi' an element associated With the track and upon which electric current may be impressed, manually operated central ollicc means for energizing or cle-energizing said element, electrical receiving devices in the vehicle, means for severally conditioning said devices in accordance with the condition of said element as effected by said cen tral office means, recording means at the central oilfice and means involving the cooperation o1c said vehicle and said element as initially cle-energized by said central ofiice means for automatically establishing an electric circuit between said vehicle and the central oiiice, said recording means being responsive in operation to said circuit. i3. ln a system of train control, the combination with a vehicle and a line of track, ot an element associated With the track and upon which electric current may be impressed, central oltice means tor energizing or Cle-energizing said element, electrical receiving devices in the vehicle, means Jfor severally conditioning said devices in accordance with the condition of said element 'as effected by said first named means, re- 'cording means at the central oilice, and means involving the co-operation of said vehicle and said element initially de energized by said first named means Vfor automatically establishing an electric circuit between said vehicle and the central. oiiice, said recording means being responsive in operation to said circuit.

7, In a system ot train control, the combination with a vehicle and a line of track, of an element associated with the track and upon which electric current may be impressed, manually operated central oiiice mea-nsfor energizing or cle-energizing said element, electrical receiving devices in the vehicle, means tor severally conditioning said devic sin accordance vith the condition of said element as eected by said central otiice means, means at the central otiice for recording the energized condition of said element as effected by said central or'lice means, means involving the cooperation of said vehicle and said element as energized by said central oHice means for producing the operation oi said recording means, means at the central ot'lice for recording the cle-energized condition of said element as effected by said central oi'licc means, and means involving the co-operation oi said vehicle and said element las initially deenergized by said central oiicice means tor producing the operation oi said last named recording means.

S. ln a system of train control, the combination with a vehicle and a line ot track, ot an element associated with the track and upon which electric current may be impressed, central oftice means for energizing or deenergizing said element, electrical receiving devices in the vehicle, means for severally1 conditioning said devices in accordance with the condition ot said element as eilected by said iirst named means, means at the central olnce for recording the energized condition ot said element as eilected by said first named means, means involving the ce-operation of said vehicle and said element as energized by said lirst named means for producing an operation of said recording means, means at the central olice ttor recording the de-energized condition of said element as ellected by said lirst named means and means involving the co-operation of said vehicle and said element as initially cle-energized by said lirst named means for producing an operation ot said last named recording means.

9. ln a system of train controlthe combination with a vehicle anda line of track, of an element associated With the track and upon Which electric current may be impressed, manually operated central oiiice means for energizing or cle-energizing said element, electrically operated clear and danger signals in the vehicle, means for establishing the operation of said signals. in accordance with the condition ot said element as effected by said central ofiice means, means at the central oiiice ior recording the danger signal and n'ieansinvolving the co-operation et said vehicle and said element as initially cle-enen gized by said central oliice means tor pro ducting the operation of said recording means.

lO. In a system of train control, the combination with vehicle and a line oit track, ci an element associated With the track and upon which electric current may be impressu ed, manually operated central office means tor energizing or de-energizing said element, electrically operated clear and danger signals in the vehicle, means for establishing the operation ot said signals in accordance with the condition et said element as effected `by said central oihce means, means at the central oilice i'or recording the danger signal, and means involving the co-operation of said vehicle and said element as initially ble-energized by said central oliice ineans iior 'automatically establishing an electric cirf cuit between said vehicle and the central oilice, the danger signal recording means being responsive in operation to said current.

ll. ln a system of tiain control, the coinbination with a vehicle and a line of track,

ot' an element associated with tlie track and Vsaidelement 'asallected lbysaid iirst named means, means at the centraholice forrecording the danger signal and means involving` tlie co-operation 'oiisaid vehicle and said element as initially cle-energized by said ilirst'named `means Flor producing the opera- .tion o'tsaid recording means.

lf2. l-lfna system of train control, the combination with a vehicle and aline of track,

- voit an element associatedv with the track and `upon '.ivliich electricv current may be impressed, central oiiicemeans'for energizing or de-y energizing said element, electrically operatedclear andwdanger signals in the vehicle,

means for establishing the .operation o'f saidsignals in accordance With the condition of isaideleinent as effected by said first named means, means'atl the centraloliice for recordiingethe danger signal, and means involving tlie-co-operation oiisaidl vehicle and said elean. electriccircuit' betweenl said vehicle and the centralzolice, the'dangei; signal recording .means being :responsive in operation to said circuit.

13. In a'systeni of train control, thecoinbination with a vehicle and a line of track,

^ upon ywhich electric current may' be iin-` pi'esseck inanually @operated 'centi-al oilice;

oiz an element associated Withy the track and inea-ns 'or 'energizing'or de-energizing-said element7 electrically,operatedclear and danger signals in the vehicle, means `for establishing the operation of said signals in accordance with the condition of said element aseiiected byy -said ceiitral-zoliice.- means, means atfthercentrall oiiice for recordingthe clearfsignal, ineansinvolving the co-ioperation of fsaid vehicle and said element asenii ergized bysaid:central'oiiiceimeans Afor producing the operationV of said: recording the operation of said last named recording means.

14. ln a system of train control, the combination With a vehicle and a line of track, of an element associated With the track and upon which electric current may be impressed, central otiice means for energizing or cle-energizing said element, clear and danger signals in the vehicle, means for establishing the operation of said signals in accordance With the condition of said ele- `ment as ellected by said irst named means, means at the central olhce iior recording a vclear signal, means involving the co-operation of `said vehicle and said element as energized by said first named means for producing the operation of said recording means, means at the central office for recording the danger signal, and means involving the co-operation oit said vehicle-and said element as vinitially de-energized by said lirstnamed means for producing the operation of said last named recording dition ot said element as effected by'said central oilice means, means at` the central oilice ior recording a clear signal, means involving the cosoperation of said vehicle and said element as energized by said central ment as initially de-energized by said first named nieansfor automatically establishing` o'liice rineans Jfor producingf'the operation of `said recording means, means at the central oflice 'or recording a danger signal and meansinvolving the co-operation ol said vehicle land said element as initially de-energized by said central otlice means for automatically establishing an electric circuit-between. said vehicle and the central oilice,v the danger signal recording means being responsive in operation to said circuit.

16. ln a system. o'ii train control, the coni bination with a vehicleiand a line oi. track, of an element associated with the track and. upon Which electric current may be inipressed, means for energizing or de-energiying said element, clear and danger signals iii-the vehicle, means for establishing the :operation of said. signals in accordance with the condition ot saidnelement as effected by -said tfirst Ynamed means, means yat the central loiiice forV recording a clearsignal ,.:meanszinvolving the co-operation of said ve cordiiigthedanger signal andineans in? 1 ifolving-"fltheI co-operation vof Isaid vehicle hicle and -saidelement as yenergized by said :irstfnamedineansi'or producing the operaaiidlf aid element. as.:initiallyicle-energizef:l .;A

.tion of said recording means', means at'the 'byLsa-idiscentralrx celmeans; forliprodncingg; eentpahgfgg. forl gemgdng.. @danger 5i-g.

lli)

nal, and means involving the co-operation of said vehicle and said element as initially de-energized by said irst named means for automatically establishing an electric circuit between said vehicle and the central oiiice, the danger signal recording means being responsive in operation to said circuit.

17. In a system of train control, the combination with a vehicle and a line of track, of an element associated with the track and upon which electric current may be irnpressed, a current source, a switch at the central oiiice and by means of which a circuit supplied by said source may be established through said element, electrical receiving devices in the vehicle, means for severally conditioning said devices in accordance with the condition of said element as effected by said central otice switch, a second current source and means co-operative with said switch in the position thereof in which said circuit is opened for closing a second circuit supplied by said second current source through said element.

18. In a system of train control, the combination with a vehicle and a line of track, of an element associated with theftrack and upon which electric current may be impressed, a current source, a switch at the central oiiice and by means of which a circuit supplied by said source may be established through said element, electrical receiving devices in the vehicle, means for severally conditioning said devices in accordance with the condition of said element effected by said central oliice switch, a second current source ot different characteristic and means co-operative with said switch in the position thereof in which said circuit is opened for closing a second circuit supplied by said second current source of different characteristic through said element.

19. In a system of train control, the combination with a vehicle, a central ollice, a line of track, and an element associated with the track and upon which electric current may be impressed, of two circuits through said element between the central oiiice and the vehicle, electrical receiving devices in said circuits, and means for automatically establishing one of said circuits when the other is opened, one of said circuits requiring for its establishment the initial deenergization of said element.

20. In a system of train control, the combination with a vehicle, a central otlice, a line of track, and an element associated with the track and upon which electric current may be impressed, of two circuits through said element between the central office and the vehicle, sources of current of different characteristics for the respective circuits and means tor automatically establishing one of said circuits when the other is opened, one of said circuits requiring :tor its establishment the initial de-energization of said element.

21. In a system of train control, the combination with a vehicle, a central oliice, a line of track, and an element associated with the track and upon which electric current may be impressed, of two circuits through said element between the central office and the vehicle, electrical receiving devices in said circuits, and means including a common manually operated central office controlling switch Jfor automatically establishing one of said circuits when the other is opened, one of said circuits requiring for its establishment the initial cle-energization of said element.

22. In a system of train control, the combination with a vehicle, a central office, a line of track, and an element associated with the track and upon which electric current may be impressed, of two circuits through said element between the central oilice and the vehicle, means for automatically establishing one of said circuits when the other is opened, one of said circuits requiring for its establishment the initial de-energiZation of said element, and recording devices at the central oiiice severally responsive in operation to the respective circuits.

In testimony whereof I afiX my signature.

PAUL J. SIMMEN. 

